The present invention relates to a hard shell capsule for the exact dosage of solid, creamy and liquid substances, especially for pharmaceutical use. The capsule has a cap part and a body part, said body part having a side wall, an open end and a closed end.
Due to the limitations of manufacture by the prior art dip-molding process, prior art capsules have telescopically joinable cap and body parts which require that the inner diameter of the cap side wall frictionally engage the outer diameter of the body side wall. When the cap and the body are joined, the open end of the cap forms a relatively sharp protruding edge on the outside surface. The prior art capsules also have the following principal disadvantages:
the capsules are neither tamper-proof nor separation-resistant if not provided with additional locking features. This is a major disadvantage if such a capsule, especially one containing food or drugs, can be opened or tampered with;
the capsules are not entirely leak-proof, especially when filled with creamy or liquid media; and
the capsules are not sufficiently tight to prevent additional oxygen entrance into the capsule which may cause oxidation of the contents.
In U.S. Pat. No. 3,653,500 there is described a method for mating filled, sealed capsules: the body of the hard gelatin capsule is made by the conventional dip-molding process, then filled and finally a drop of molten gelatin is placed over the body's open end in contact with the filled material. In this prior patent the sealed capsules show edges on the top where the drop of molten gelatin has fused with the open end of the capsule body.
In the present invention, the following considerable improvements over the prior art are disclosed:
the capsule body is made by a dip-molding or by a die-molding process;
the cap part is die-molded or extruded onto the body part; and
the capsule is tamper-proof and has a smooth outer surface.
It is an object of the present invention to provide a capsule with the aforementioned advantages.
It is another object of the present invention to provide a capsule which is liquid, moisture vapor and gas tight.
The advantages of the present invention will become apparent to those skilled in the art from a consideration of the detailed description which follows with reference to the accompanying drawings.